Brachial Plexus Injury

Injury to the brachial plexus can reduce or destroy sensation or movement in the arm or hand. At the Peripheral Nerve Center at Columbia University Irving Medical Center/NewYork-Presbyterian Hospital, we treat brachial plexus injuries with procedures that include nerve repair, nerve graft and nerve transfer.

The brachial plexus is a network of nerves that link the spinal cord and the nerves of the arm. Injuries to the brachial plexus range from minor to severe.

Minor injuries usually do not require surgery. However, even minor injuries should be evaluated, as there are windows of time during which treatment for nerve injury is most effective.

Most people who are candidates for surgery have experienced severe nerve injuries called avulsions, ruptures, and lacerations. A single serious trauma to the neck, arm, and/or shoulder can deliver a combination of these injuries.

An avulsion is the most severe brachial plexus injury. In an avulsion, the nerve root is disconnected from the spinal cord, resulting in a partially or fully paralyzed arm. Though this is the most difficult type of peripheral nerve injury to treat, we perform several surgical techniques that may permit the recovery of useful function even after an avulsion. Ruptures and lacerations can also have devastating effects on nerve function, but many of these injuries can be repaired using the surgical treatments described below.

Symptoms

Each of the five nerves of the brachial plexus has a specific function. Symptoms of brachial plexus injury depend on the extent of injury to each nerve. Specific patterns of avulsion, rupture and/or laceration in the plexus are typical of certain types of trauma. For example, a motorcycle accident in which the shoulder is pressed forcefully away from the neck/head on impact with the ground will tend to produce one pattern; injuries sustained when a person grabs something to break a long fall, yanking the arm forcefully up away from the body, yield a different pattern of injury.

Avulsions, ruptures, and lacerations all produce symptoms that may include weakness or paralysis, paresthesias, numbness, and/or pain in the shoulder, arm, hand, and/or fingers.

Diagnosis

Each nerve of the brachial plexus controls sensation and movement in a different part of the shoulder, arm, hand, or fingers. Comprehensive physical examination may allow medical personnel to determine which nerves of the brachial plexus are affected and to what extent.

Trauma that causes injury to the nerves may also cause injury to blood vessels, muscles, tendons, ligaments, and bones. Imaging studies such as X-ray, MRI and CT scan may be of use in identifying such injuries.

A scan called a myelogram can examine the spinal cord, nerve roots, and nerves. A myelogram can also identify whether there is a collection of cerebrospinal fluid (CSF) in the tissues near the spine. CSF is normally contained inside a protective “envelope” around the spine, and this can be ripped during an avulsion. Thus this collection of fluid, called a pseudomeningocele, is often present with nerve root avulsion.

Risk Factors

Most commonly, severe brachial plexus injuries result from motor vehicle accidents—especially motorcycle accidents. Severe injury can also be a result of gunshot or knife wounds, or a fall from a significant height.

An infant may sustain brachial plexus injury during a difficult childbirth. Risk factors for obstetrical brachial plexus injury include infant in a breech presentation, infant very large for gestational age, and a prolonged second stage of labor. Obstetrical brachial plexus injuries often heal completely or nearly completely without surgery. However, obstetrical injuries that do not heal on their own may be treated with surgery.

Treatments

A nerve transfer can help when a nerve has been severely damaged. In this procedure, a healthy nerve is taken from its original location and inserted into a different location where the nerve supply has been damaged. The connection between the healthy nerve and the spine remains intact; the transferred nerve simply brings its motor or sensory abilities to an area that had lost them. In this fashion, less useful functions may be sacrificed or diminished so that more important functions may be regained.

Shoulder abduction is commonly lost following some brachial plexus injuries. Two common nerve transfers performed to restore shoulder abduction are the accessory-to-suprascapular nerve transfer and the triceps branch-to-axillary nerve transfer. Arm flexion, another common casualty of brachial plexus injury, may be restored with the ulnar-to-musculocutaneous nerve transfer or the intercostal-to-musculocutaneous nerve transfer.

Another surgical option for treating brachial plexus injury is the nerve graft. This procedure can be useful when it is necessary to bridge a gap between two cut ends of a nerve. During a nerve graft, a section of healthy nerve is taken from elsewhere in the body and sutured in place, connecting the ends of the cut nerve. Nerve grafts may be used to restore either movement or sensation.

Most commonly, sensory nerves are chosen as donor nerves. Following the procedure, the area previously supplied by the donor nerve will no longer be capable of sensation—that is, it will be numb. The most common donor nerve is the sural nerve, taken from the calf, resulting in numbness in part of the foot.

A muscle transfer may be useful for some types of brachial plexus injuries. In a muscle transfer, a section of healthy muscle from elsewhere in the body is removed and transplanted to an area that has lost muscle function. Along with the transplanted muscle must come its major artery and vein (along with its smaller arterioles and venules), which must be sewn into a blood supply in the new location, as well as the muscle’s healthy nerve, which must be attached in place of the existing, damaged nerve.

The Peripheral Nerve Center team is experienced with these and other procedures for treating brachial plexus injury, and they can determine the best treatment or combination of treatments for each individual.